


Upstream

by GlitterGluwu



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Alternate Universe - Modern Setting, Cunnilingus, F/M, Omorashi, School Dances, Semi-Public Sex, Sibling Incest, Squirting, Underage Drinking, Underage Sex
Language: English
Status: Completed
Published: 2020-10-29
Updated: 2020-10-29
Packaged: 2021-03-08 17:28:16
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 3,616
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27270445
Author URL: https://archiveofourown.org/users/GlitterGluwu/pseuds/GlitterGluwu
Summary: “If you want to help me, then start a conversation with Ms. Charon.”“Why her?”“Because,” Edelgard hissed through her teeth, “I’ve been to the bathroom too many times, and she’s going to start questioning why.”Dimitri was missing something. “Why would she care?”She gave him an exasperated look. “If you’re trying to punish me preemptively, then you can cut it out. I know it’s stupid, but it’s not as if I expected to get literally piss-drunk before getting home.”The realization hit like a rock to the gut.---Dimitri and Edelgard run with different crowds. Unfortunately for Edelgard, her body's not very used to alcohol yet.
Relationships: Dimitri Alexandre Blaiddyd/Edelgard von Hresvelg
Comments: 7
Kudos: 44
Collections: Dimigard Week





	Upstream

**Author's Note:**

> I didn't exactly _mean_ for this to be a matched set with Downstream, but I guess it works? This is the Dimitri-POV, silly meaningless porn to match the Edelgard-POV feelingsy porn that that fic presented. And they're my two Actual Fics for Dimigard week, so that's a plus.
> 
> Anyway, this is definitely not influenced in any way by the fact that my own bladder seems to shrink to the size of a pea anytime I get drunk in spite of me being twenty-four years old and well past the point where that should be an issue. Absolutely not. Enjoy! And check out [Dimigard Week](https://twitter.com/dimigardweek) if you haven't already, there's a TON of great stuff being produced from it.
> 
> Thank you also to [Nat,](https://twitter.com/nishtabel) who was my beta for this as well as Downstream and also my consultant for How To Write Drunk Teens, because when I was a teen, on a scale from Edelgard to Dimitri..... I was Dimitri.

The school gym was, as one might naturally expect, packed to the brim. It hadn’t been yet, when Dimitri first arrived - himself, Ashe and Ingrid were all naturally geared toward punctuality, however much Annette begged to put it off until they could reasonably be called fashionably late. “It’s going to be so  _ weird,” _ she’d grumbled when she was outvoted. “Everyone’s gonna be looking at us!”

“Dimitri and I have waited long enough to have seniority in our group. If you care about blending in, you should’ve come with us before Sylvain graduated - or convinced Felix to come,” Ingrid had countered - and as much as Dimitri might have taken issue with the tone, she was right. He was glad to be listened to.

Of course, nobody was paying near as much attention as Annette seemed to believe they would - none of the particularly talented dancers were among them, after all. It only took about half an hour of subdued bouncing as a pack for Annette to embolden herself into hopping in place and merrily shouting along to the present moment’s inoffensive pop star.

That was long enough for Edelgard’s group to arrive. Miffed as Dimitri still was that she’d elected to come with a separate group from his, he  _ could _ understand the appeal - hers was more raucous, more well-populated, and didn’t have her  _ brother _ in it. In fact, the gym itself seemed to come alive when they finally showed, already alight with laughter, pulling each other onto the dance floor before they’d so much as caught their bearings.

Edelgard, in fact, was among the more subdued of them - including the youngest of their group, an exchange student named Petra who almost immediately gathered a crowd with her very  _ acrobatic _ dancing - as she lingered at the edge of the crowd, smiling into her palm and watching Dorothea teaching Caspar some moves. Ferdinand parted from them soon afterward, leaving only Linhardt and a somewhat ruffled Bernadetta to keep Edelgard company.

She spared Dimitri a glance at last, and when he waved, she waved back, albeit with visible reluctance. He frowned, watching her lean in to share a brief, whispered conversation with Linhardt, who pitched forward in laughter.

That was… Out of character.

“Slow dance,” Ingrid pointed out, and as Dimitri fell into natural step with her he lost track of his sister.

He did catch sightings of Edelgard over the course of the next hour or so - getting snacks at the edge of the crowd, learning a thing or two from Dorothea and Petra, coaxing Bernadetta into a slow dance before she ultimately disappeared for the night. He lost sight of her a few times, though, either because she took frequent trips to the restroom or because her company was just that distracting. 

Of course, the revelation came during another slow dance. He chose to sit this one out and was peacefully observing Ingrid and Ashe swaying together when he overheard a familiar voice say “Can’t believe I’m this drunk already, I only had -”

“Caspar,” Linhardt chided him, and when Dimitri turned to look, he caught the briefest flicker of Linhardt’s gaze on him before he quickly looked away, back toward his dancing partner. “Surely even you realize that’s a thing to keep  _ quiet _ about.”

Dimitri didn’t miss the significance of Caspar’s quick, panicked glance toward him, but he was nonetheless discomfited. He knew very well that his group was hardly typical, but Caspar and Linhardt were… well, younger than  _ him, _ which made them feel like children. He heard Caspar stumble as he got to his feet and walked away from the dance floor, casting subtle glances around for the rest of Edelgard’s group; Dorothea seemed alright, but being the eldest she might well have been the source to begin with. Ferdinand was bold and talkative as ever, though Dimitri did notice  _ Lorenz _ leaning distastefully away from him as he babbled. Bernadetta was gone, but the fact that she’d been convinced to come at all…

He encountered Edelgard lingering like a ghost near the door to the hallway, her arms folded over her chest and her entire body stiffer than he was used to seeing it. She was casting anxious glances toward the door, and Dimitri felt for her.

She gave him a terse little smile, though her eyes were wider than he was used to seeing them. He arrived at her side, leaned against the wall next to her, and whispered, “I’m sorry. When did you find out?”

Her reply was delayed. “What?”

He tilted his head subtly toward Ferdinand, who, conveniently, was presently spilling punch on himself. “Edelgard, if you’re uncomfortable, you are always free to tell me. Ingrid has her own car, I’d happily drive you home.”

He watched her swallow and bounce on the balls of her feet. “I don’t think a ride in a car will help me right now,” she muttered. Her face was dark, and Dimitri realized it was with a blush; blue and green lights danced over it as she bit her lip and he wondered whether he’d misread the situation. “If you want to  _ help _ me, then start a conversation with Ms. Charon.”

Dimitri cast a perplexed glance toward the door, where their teacher had propped herself and was idly looking around the gym. “Why her?”

_ “Because,” _ Edelgard hissed through her teeth, “I’ve been to the bathroom too many times, and she’s going to start questioning why.”

Dimitri was missing something. “Why would she care?”

She gave him an exasperated look. “If you’re trying to punish me preemptively, then you can cut it out. I know it’s stupid, but it’s not as if I  _ expected _ to get literally piss-drunk before getting home.”

Dimitri processed this statement. It hit like a rock to the gut. “You’re -”

_ “Please, _ spare the lecture, I  _ have _ to go,” Edelgard begged, and there was so much to  _ process -  _ her posture, the upward lilt of her voice, the  _ slur _ that he was only now recognizing. He gaped, trying to filter through the shock, the disappointment -

“Who - How were you planning to get  _ home -” _

_ “Dima,” _ she insisted, beseeching him with every part of her - her eyes were so wide, almost tearful now. Her thighs were pressed tightly together, her shoulders curled inward, and much as Dimitri felt he needed to chastise and correct, he was also aware that his sister was halfway to panic.

He deflated around a sigh, peering over Edelgard’s head toward Ms. Charon, then around the room. Ms. Charon was a very personable teacher, but no less a strict one - he liked his chances better further around the room toward the exterior door, where Ms. Nevrand was picking at her nails. He gently grasped Edelgard’s arm and pulled, leading her in the opposite direction, searching his mind for excuses, for  _ anything - _

Edelgard drew to a halt with a squeak, audible even above the din from the speakers. Dimitri cast an irritated glance back at her, about to serve her some snark about how  _ she’d _ insisted that he help, but he found her pitched forward, clutching at her stomach, her eyes squeezed closed and her thighs pressed together to the knee.

He glanced down. There was one rivulet rolling down her leg, darkening her tights, and his heart skipped a beat.

Why was  _ he _ so affected by this? His lungs strained for air as he gently placed a hand around Edelgard’s shoulder, silently coaxing her forward, trying to shield her from the rest of their classmates as best he could. For what it was worth, once she got ahold of her bladder again - and he struggled not to be impressed with the willpower  _ that _ took - he took a certain pleasure in how she allowed herself to be led. She so seldom let him be a brother to her, nowadays.

Dorothea took a cautious step toward them as Dimitri led Edelgard to the exit, but was easily dissuaded with a pointed glare. Affronted as her counter was, it got them to Ms. Nevrand without further event.

“Apologies,” he said, getting her attention. She raised her eyebrows at Edelgard, but when Dimitri explained, “She’s not feeling well. Could we get some air?” she allowed it easily enough.

Edelgard put up a good front, but it crumbled when they got outside. She glanced around as if only now realizing where he’d led her and said, “Dimitri, I need a  _ bathroom.” _

He parted from her, feeling her heat clinging to him, and indicated the ground. “Plenty of space to relieve yourself, El. And in the meantime, I have a bone to pick with you.”

“Wait,” she whined, pulling up her dress, and the speed with which it took place startled him enough that he almost forgot to look away - and then she was pulling at the waistband of her tights and his head snapped around like whiplash, heat blooming on his cheeks as he heard the telltale fizzing of urine hitting grass.

Her gasp of relief could have come straight out of - no,  _ no, _ heavens no, he was not going to think about that.

“Father is going to be furious,” he said, in an effort to distract himself. Edelgard whined again.

“Please don’t tell him.”

“I won’t have to! Did they not promise to wait up for us?!”

“Please.”

The drink in her voice was easier to parse, with the music thrumming indoors instead of blasting in their ears. It was that much more apparent for the fact that they were in the gym’s shadow, sandwiched in that seldom-traversed part of the school between the hulk of two different sections, with nothing of note to look at except for patchy grass and Edelgard herself.

“How did you even plan to get  _ home,” _ Dimitri muttered, not wanting to make any promises yet. Grass shuffled behind him and Edelgard groaned.

“I sat in my own pee,” she pouted.

“Will you  _ stop  _ acting like a child, El!” he snapped, rounding on her, thoroughly unprepared for what he’d see - Edelgard struggling to remove one of her shoes, her tights tangled around her legs, and her skirt still bunched at her middle, baring her privates.

She pursed her lips, glaring up at him from the ground. “Between the two of us, it’s not  _ me _ who acts like a child.”

Dimitri huffed, fighting to keep his eyes above her waist. This didn’t have to be weird. She was his  _ sister. _ “I honestly don’t know who so eloquently convinced you of that, because  _ surprise - _ only children pee their pants.”

That was enough to enforce a couple moments of silence as Edelgard carried on removing her shoes, then pulled her tights off after them. As she puzzled over where to leave her piss-soaked tights, Dimitri noticed something else.

“You - El,” he sighed. “You’ve… You’ve neglected underwear.”

“Mm?”

“You’ve forgotten to wear  _ underwear.” _

“The word ‘forgotten’ implies that I ever intended to wear any,” Edelgard replied, leaving the tights in the grass for now and setting in to put her shoes back on. Her legs were still spread, her bare cunt still pale against the darkness of the grass. “I was planning on doing more than just getting drunk and being lectured to tonight.”

In all honesty, Dimitri didn’t know how he managed to  _ feel _ surprise anymore. “Are you - you’re serious. If Father discovered you stayed the night with a boy, he’d  _ kill _ you.”

“No need to worry,” Edelgard said, and her voice all but  _ swooped _ downward - huskier, suddenly, taking on an almost seductive tone as she finished putting her second shoe on. She leaned her head on her knee and winked. “Daddy won’t kill me for this sleepover, because he doesn’t know I’m bisexual yet.”

That was… A surprise.

“Did you mean to - never mind,  _ that _ can wait until you’re sober,” Dimitri groaned, stepping forward to allow Edelgard to use him as a makeshift ladder to get back to her feet. “El, I’m sure Dorothea or… Whoever… will have the sense  _ not _ to - to take advantage of you, when you’re this inebriated. It would be incredibly irresponsible.”

“Oh?” Edelgard hummed, leaning into his side for further support. “And I suppose  _ you _ are the paragon of responsibility?”

“Compared to you -”

“I’m not the one with the hard-on, brother mine,” Edelgard whispered, and he was just peering down into her heavy-lidded gaze when she palmed his erection.

He jumped - Edelgard stumbled - and he bit down his yelp as he scrambled to displace Edelgard’s hand, so many parts of him instantly feuding with each other. His groin tingled, his cheeks burned, and his stomach turned; he couldn’t believe he’d become hard without realizing, and he  _ certainly _ couldn’t believe Edelgard would be - so -

_ “El,” _ he hissed, scandalized, and she giggled into his chest, shifting against him - side to side - pressing into him in a way that made him  _ want _ harder than he’d expected he could. “S-stop - I know you’re drunk, but -”

“But you’re not,” she teased, and he felt one of her petite fingers worming between the buttons of his dress shirt, gently tickling his chest. “My big, strong,  _ responsible _ brother is entirely sober, and he got hard for his sister.”

“El,” he tried, one final time, halfway to breathless. She met his eye and held it, continuing to pick at his buttons - and undoing one of them - until she cocked an eyebrow.

“I’m just teasing,” she said softly. Dimitri was hardly convinced, and she seemed to know as much; “Dorothea teases everyone like this.”

Her warmth was intoxicating. He still had so many questions on his mind - where had they gotten the alcohol, who had gotten it for them, how had they planned on getting  _ home - _ but she was pressing on him, depressing that tent in his pants, making his breath catch with every minute little shift. He struggled for words, knowing he couldn’t let this slide, but  _ knowing _ this was the most affectionate she’d been in  _ ages - _

Her eyes grew wide, and he thought he’d done something wrong. Then he felt it - warmth spreading on his thigh, soaking in through his pants, a sensation of heat first, then wetness. As crossed as his wires were, he wondered whether this was what it felt like when a girl got “wet.”

And Edelgard - her eyebrows tented in relief and a short, soft gasp escaped her, as high and as nasal as she’d sounded when she’d been - relieving herself -

He realized what was happening just as she finished, shocked to the point of numbness. She opened her eyes, relieved - and then, all at once, horrified.

“I thought I was - I’m so sorry,” Edelgard said, her entire face darkening with a flush, “I-I thought I was done.”

She tried to peel away - he felt it, her moving, and that first parting of their forms crested a tidal wave of desire inside of him. He didn’t think - just grabbed her shoulders and swiveled into the wall, pinning her against it, looking down toward her shaking legs to see another stream forming, snaking around her calf and dirtying her shoe as he watched.

He  _ wanted _ to watch. He longed for it, with his cock and - and indeed, with his heart.

Dimitri crouched, half-heartedly muttering, “I can’t believe I’m…” before lifting Edelgard’s skirt and watching her finish her  _ third _ piss of the last ten minutes. Her pubic hair formed into distinct sections, clumped together by the trickle of fluid. Some part of him - some distant,  _ distant _ part of him, living in his stomach and quietly roiling, still rebelled at the thought that  _ this was his sister. He should be disgusted, he shouldn’t want anything to do with this. _

He bent forward and kissed the very top of her slit, shuddering in delight, and Edelgard squeaked a million miles above him. Her thigh twitched and he grabbed it on instinct, squeezed, thrilled at her unique softness. He kissed her cunt again, feeling piss coating his lips; she’d stopped urinating, but the act was everywhere around him: in the pungent odor lingering between her legs, in the cooling patch of wetness on his pants, in the trails of liquid his hand passed through as he mindlessly groped up and down her thigh.

“And you thought -” he rumbled, kissed her again - oh, her sounds were  _ delicious - _ “Y-you thought  _ you _ were the adult, between us.”

Her knees wobbled, she whined high in her throat. Dimitri indicated her skirt with that hand, and she at last took it, holding it up for him to carry on with his business. He took to that with relish, at last parting his lips and twitching at the first, sharp taste of urine; between the scents accosting him and the  _ feeling _ of her all around him, it was very nearly too much. But then he tongued a little deeper, lapped a little lower, and - she tasted different here. The two tastes were each as harsh as the other, but they were that much more improved just for knowing where he was and what he was doing.

_ Like the fact alone that it was Edelgard. _

There was  _ still _ a part of him trying to convince him of how very wrong this all was, nagging at the most distant border of his mind as he drew his tongue up over silky-smooth inner labia. It lost steam with every throb of his cock; if anything, the fact that she was his sister - that they’d grown up together, that they’d once looked at the differences in their bodies with naught but an almost scientific interest - had morphed into another draw, another body sensation sitting heavily - anxiously - disgustedly - in the pit of his stomach, acting as complement to his arousal or his lightheadedness.

Lightheaded. Indeed, he was almost drunken on the assault of sensations. He wondered whether it was possible to get  _ really _ drunk on a drunk person’s urine, or if he was just that sick in the head.

“Di - mahhhh,” Edelgard moaned, little more than a voice behind the barrier of her skirt now. Dimitri had half a mind to warn her to be quieter, but - but the sounds were yet another tantalizing treat, one he wasn’t nearly strong enough to refuse. He coaxed another out of her with a deeper swipe of his tongue, half-surprised to find her entrance as he did. That’s right…

He worked his way back up her slit, nearly reluctant to remove his hand from her thigh - she was shaking so viciously, he wondered whether she could even hold herself up anymore. She did stay standing, though, even as he found the little peak he’d heard so much about. 

Her cry was enough to make him shudder, at last groping along his length as he sealed his lips around her equivalent anatomy; it was firm, contrasting the  _ softness _ of the rest of her, and he whined into her tart taste. He circled his finger along his own clothed tip, so close - so  _ close _ already, engulfed in the bliss of her, so far separated from reality. The music inside could never have thrummed so deep within him as the throbbing of her clit against his lips or her heated moans, the rhythmic jostling of bodies never so overwhelming as two slim legs aquiver on either side of him.

He squeezed her thigh with his free hand once more and realized - there was more he could be doing, yet more blissful sounds he could pull from her. He pulled his hand from her skin, worried for a moment that she would collapse - and yet she didn’t. She just panted, unassuming and lost in her own world, until he brushed his thumb along her lips.

“Oh,” she gasped, and this was bliss, too, feeling her lips parting in two places, feeling her clit twitching in his mouth. He flicked it with his tongue and felt her buck into his face, startled for a moment but carrying on nonetheless. He erred for a moment before choosing his middle finger - the longest and thickest, which he’d heard made for the best experience for her - and sank it into her cunt.

Her legs gave out. She cried, long and loud, as Dimitri held himself firm, not so much at risk of collapsing beneath her weight as  _ surprised -  _ especially when yet more liquid gushed down over his chin, pouring in rivulets over his neck, engulfing him in pride and overwhelm. Had he made her squirt, he wondered, or had she just lost control for a fourth time?

He groped listlessly along his cock again, out of his mind with overthink - what had he done, what did this  _ mean -  _ but floating, floating, out and out drunk on her scents and tastes and - oh, how childish  _ was  _ it, not to lose control of one’s bladder but of one’s orgasm, to release in his pants instead of urinating in them?

She’d lifted herself off of him by the time he finished, gasping, savoring the wet heat in his pants for as long as he was able. She was still standing above him, however, visibly swallowing her arousal.

“Th-that was,” she mumbled, and he was prepared for several things - was it wrong? Did she hate him for taking advantage of her? - but no, she finished with, “M-my first one.”

He groaned. He couldn’t help it.

Everything about her, from her strapless dress hanging low on her meager breasts to the sweat glistening on her collarbone to her half-undone updo, begged sex from him. He wanted so much to - to fall back on the same excuse, to say that the things he was envisioning, the thoughts tumbling around in his mind, were the fault of alcohol, a responsibility that he had shirked not through willfulness but through neglect.

Instead, he mumbled, “Father is going to be furious.”

**Author's Note:**

> If you've read this far, consider leaving a comment!!! Fic writing can be hard, even when it's just some silliness about drunk teenagers and pee.
> 
> [My Twitter!](https://twitter.com/glittergluwu) | [My CuriousCat!](https://curiouscat.qa/GlitterGlue)


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